Related Molar mass 552.67 g/mol | Formula Fe4N7NaO7S3 Appearance Black needles | |
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Roussin's black salt is a chemical compound with the formula NaFe4S3(NO)7 first described by Zacharie Roussin. It consists of the sodium salt of the [Fe4S3(NO)7]− anion and is classified as metal nitrosyl compound. The cluster anion has the geometry of an incomplete cubane-type cluster with C3v symmetry. The dark colour of the complex is attributed to a number of charge-transfer interactions.
Contents
Synthesis
Roussin’s Black Salt is produced by the reaction of nitrous acid, potassium hydroxide, potassium sulfide, and iron(II) sulfate in aqueous solution. It can also be formed by the conversion of Roussin's Red Salt in mildly acidic conditions. This reaction is reversible and Roussin’s Red Salt is reformed upon alkalization of the reaction solution.
Uses
Roussin’s Black Salt is a nitric oxide donor. The nitric oxide donated by Roussin’s Black Salt has proven to be toxic to some melanoma cancer cells. Also, Roussin’s Black Salt exhibits antibacterial activity in some food processing applications.